1. Field of the Invention
The present invention relates to sealants and, more particularly, to pavement sealants and, most particularly, to a pavement sealant that can be heated to remove ice and/or snow from the sealed pavement surface.
2. Background Information
The road system of many countries extends over millions of miles. In order to provide a durable surface that withstands the elements of weather, the majority of roads and streets are paved with concrete or asphalt, although bricks or stones are used in a few instances. In temperate climates, such paved roadways receive rain, or snow and ice during colder portions of the year. If the pavement develops cracks, liquid water can penetrate the cracks and cause deterioration of the integrity of the pavement. Rather than completely replace the pavement when cracking occurs, a sealant is commonly applied to the surface of the pavement to seal the cracks from the water. The commercially available sealants are fluid materials that are applied to the cracks or applied to the entire paved surface for protection. The sealant fluid is commonly an aqueous emulsion of various petroleum products, such as asphalt (petroleum refining residues) or coal tar (residue from destructive distillation of coal). Sealants are specialty coatings that are used for the protection and preservation of paved surfaces. The name itself defines the role; a coating that acts as a shield to protect components in the pavement, thus “locking-in” or “sealing-in” the redeeming properties of pavement. Water-based sealants are semi-fluid compositions, which are essentially fine dispersions of a binder component (coal tar or asphalt), in a clay/filler-water slurry. Such compositions are stabilized by specialty chemicals and additives. The fluid sealant is applied to the pavement and the aqueous fraction is allowed to evaporate to form a protective coating on the surface of the pavement.
Some sealant products contain an organic carrier fluid, such as oils derived from oil seeds, including linseed oil, soy bean oil, rape seed oil, etc. These organic liquid carrier fluids react chemically with oxygen in the air, and thus are incorporated into the sealant as it dries.
In addition, snow and/or ice can accumulate on paved roads, which results in a hazard to vehicles traveling over the pavement. In order to remove the snow/ice from the roadways, municipalities routinely apply salt or salt/sand mixtures to the roadways. The salt melts the snow/ice to clear the pavement, but the resulting salty water is of environmental concern.
Thus, there is an unmet need for a system that can maintain a paved roadway free of ice and snow, with minimal environmental effects, as well as seal the paved roadway to maintain the integrity of the pavement surface. Applicant has devised such a system for maintaining a paved roadway free of ice and snow with little effect on the surrounding environment.